Choset and his students have engineered a highly articulated robotic arm that consists of multiple actuated joints, which give the robot a snakelike flexibility. Each joint has two degrees of freedom that, working together, allow the robot to flex, retract, and twist into different configurations, much like a live snake.
Because it’s impossible for a person to simultaneously control all the joints on the snake, the team developed software to enable precise control of the robot’s movements via a joystick. In lab tests, researchers could successfully guide the arm, mounted with a camera, up and down a skeleton’s body using the joystick and watch the resulting pictures on a laptop.
Choset has affixed various physiological sensors to the robotic arm, including a detector for carbon dioxide and oxygen to test whether a person is breathing. He says that the robot can also sport an oxygen mask and, if connected to the stretcher’s onboard ventilator, can potentially maneuver over a soldier’s mouth and deliver oxygen, without the help of a medic.
In the future, Choset hopes to add an ultrasound component to the robot, so that it can quickly scan a soldier for signs of internal bleeding. His team is collaborating with researchers at Georgetown University to develop an ultrasound probe for the robotic arm. To perform ultrasound, Choset says that the robot would require a certain amount of strength and delicacy so that it can determine how much force to apply to gently press a probe against the skin. He and his students plan to explore this robotic challenge in the future, along with other applications for the snake robot.
Sylvain Cardin, a senior medical robotics scientist at TATRC, suggests that there may be other military applications for the robotic arm. “It could be on a small vehicle you could send into the field, and the medic could attend the patient in a remote location,” says Cardin. “So you could be under fire, and could send this little vehicle out with the snake arm, and be able to attend the casualty without showing everyone we’re attending the casualty.”